Method and device tolerant to direct current source fluctuation for pulse charging a battery

Abstract

A method for charging a battery ( 16 ) from a direct-current source liable to significant fluctuations, which includes the steps of: progressively charging a storage capacitor ( 14 ) at a voltage that is higher than the nominal voltage of the battery ( 16 ), detecting a predetermined voltage threshold over the terminals of the storage capacitor ( 14 ), and discharging the storage capacitor ( 14 ) into the battery ( 16 ), the discharging being controlled by the threshold detection.

1. A method for charging a battery from a direct-current source liable to significant fluctuations, comprising the repetitive steps of:
 converting the DC voltage from said direct-current source into a DC voltage which is higher than the voltage of said battery, 
 applying said higher DC voltage to the terminals of a storage capacitor, so as to transfer energy into said storage capacitor, 
 detecting a predetermined voltage threshold over the terminals of said storage capacitor, and 
 upon detection of said voltage threshold, connecting said storage capacitor to said battery during a predetermined time, so as to transfer energy of a discharge pulse with predetermined energy from said storage capacitor into said battery. 
 
     
     
       2. The method of  claim 1 , implemented for charging a battery from a photovoltaic cells source. 
     
     
       3. The method of  claim 1 , implemented for electrically supplying a lighting equipment for a vehicle, from a bicycle dynamo-electric generator. 
     
     
       4. A device for charging a battery from a direct-current source liable to significant fluctuations, implementing the method according to any of preceding claims, comprising:
 means for storing capacitive energy, 
 means for converting the DC voltage from said direct-current source into a DC voltage which is higher than the voltage of said battery, 
 means for applying said higher DC voltage to the terminals of said capacitive storage means, so as to transfer energy from said converting means into said capacitive storage means, 
 means for detecting a predetermined voltage threshold over the terminals of said capacitive storage means, and 
 means for connecting said capacitive storage means to said battery during a predetermined time, so as to transfer energy of a discharge pulse with predetermined energy from said capacitive storage means to said battery, said connecting means being controlled by said threshold detection means. 
 
     
     
       5. The device of  claim 4 , characterized in that it further comprises filtering means ( 11 ) arranged between said direct-current source and said progressively-charging means ( 13 ). 
     
     
       6. The device according to  claim 4 , characterized in that it further comprises means for adapting the predetermined voltage threshold at the terminals of said capacitive storage means ( 14 ), in function of the type of battery to be charged. 
     
     
       7. The device according to  claim 5 , characterized in that it further comprises means for adapting the predetermined voltage threshold at the terminals of said capacitive storage means ( 14 ), in function of the type of battery to be charged. 
     
     
       8. The device according to  claim 6 , characterized in that the threshold-adapting means comprise a commutable resistor ( 35   a ,  35   b ,  35   c ). 
     
     
       9. The device according to  claim 7 , characterized in that the threshold-adapting means comprise a commutable resistor ( 35   a ,  35   b ,  35   c ). 
     
     
       10. The device of  claim 4 , characterized in that the progressively-charging means ( 13 ) comprise inductive storage means ( 29 ) cooperating with controlled switching means ( 28 ).